The present invention relates to a combustion-type power tool, and more particularly, to such power tool capable of providing sufficient combustion efficiency.
In a conventional combustion-type driving tool such as a nail gun, a gaseous fuel injected into a combustion chamber is ignited to cause gas expansion in the combustion chamber, which in turn causes a linear momentum of a piston. By the movement of the piston, a nail is driven into a workpiece. Such conventional combustion-type driving tool is disclosed in U.S. Pat. No. 4,483,280, Re 32,452 and U.S. Pat. No. 5,197,646.
In the above-described conventional combustion type power tool, heat generated upon combustion of a fuel in the combustion chamber is robbed or absorbed at the inner surface of the combustion chamber, so that the combustion is restrained prior to complete combustion of the fuel. Thus, driving output for striking the nail may be lowered because combustion efficiency is lowered.